PLE-7723

A 52-year-old woman, gravida 3, para 3, comes to the physician because of irregular vaginal bleeding over the past 2 months. She has hypertension treated with enalapril and type 2 diabetes mellitus well controlled with diet. Menopause occurred 2 years ago. Her maternal aunt had breast cancer at the age of 70 years. The patient weighs 88 kg (195 lb) and is 160 cm (63 in) tall. Examination shows no other abnormalities. An endometrial biopsy specimen shows adenocarcinoma. What is the most significant predisposing factor for this patient’s endometrial cancer?